The customs regime, passed by 208 votes to 184, suspends export and import duties on goods used in oil exploration and production.

Brazil’s lower house has approved the basic text of a decree extending by 20 years a preferential customs regime for the oil industry, a move criticized as a gift to global oil giants at the expense of the Brazilian people.

The chamber is due to vote next week on several amendments to the decree, introduced by Interim President Michel Temer, but the extension is expected to move ahead to the Senate for final approval before the Dec. 15 expiry date.

Leftist lawmakers, one after another, blasted the decree for four hours to try to block a vote, arguing that it handed over Brazil’s oil riches to foreign companies such as Royal Dutch Shell and BP.

Such a move would deprive the Brazilian treasury of US$13,000 billion every year in tax revenues until 2040 – the estimate by Congress accountants. The lawmakers said it would sink the national shipbuilding industry which makes off-shore oil platforms.

President of the Socialism and Freedom Party Luiz Araújo said the development was tantamount to stealing money from the Brazilian people, while Head of the Workers' Party Carlos Zarattini described it as a "loss of sovereignty."

Zarattini quoted official documents leaked two weeks ago by the Guardian, detailing how the government successfully lobbied on behalf of British Petrolium and Shell with Brazilian authorities in order to ease tax regulations for the oil giants.

A group of opposition senators has filed a complaint to the attorney general, accusing the British and Brazilian governments of favoring both firms in last month's auction of six blocks in the pre-salt region, where billions of barrels of oil are trapped below thousands of feet of salt in the Atlantic.